Frank a



Patented Jan. 25, 1898.

INyENTD'Ff a W ATTY (No Model.)

1". A. BURNHAM. TYMPAN FOR PLATEN PRINTING PRESSES. No. 597,952.

UNITED STATES PATENT Erica.

FRANK A. BURNHAM, OF CLEVELAND, OHIO, ASSIGNOR TO THE CHANDLER do PRICE COMPANY, OF SAME PLACE.

TYMPAN FOR PLATEN PRlNTING-PRESSES.

SPECIFICATION forming part of Letters Patent No. 597,952, dated January 25, 1898.

A Application filed July 22, 1897. Serial No. 645,553. (No model.)

V a citizen of the United States, residing at Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Tympans for Platen Printing-Presses; and. I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in tympans for platen printing-presses; and the invention consists in a tympan provided with means for stretching and evening the paper or other cover therefor after the bails have been fastened down over cover at the edges of the tympan in the usual way, so that thereby any wrinkle or unevenness in the cover or any objectionable looseness thereof can be taken up and remedied and the covering be made smooth and even across its entire width.

In the accompanying drawings, Figure 1 is a plan view of a platen or tympan bed embodying my improvement. Fig. 2 is a side elevation of Fig. 1, looking in from the right of said figure and showing the bails which secure the tympan-cover in partially-raised position. Fig. 3 is a cross-section of Fig. 1 on line 3 3.

A represents a platen of any usual construction, and B is a supplemental frame-like part or device adapted to be supported along the front and sides of the platen, substantiallyas shown, and having right-angled extensions or arms at its ends engaging the said sides or edges of the platen. This supplemental frame thus constructed is held in adj ustable relation to the platen by means of screws 2, engaged in the platen through slots in the side arms or extensions of the frame B, and pins 4: in the platen working in slots 5 in said side arms. Thus only a back-and-forth adjustment of this frame B is provided for and needed, and the tympan sheet or cover D is engaged over or upon the said part instead of engaging over the edge of the platen, as usual heretofore. Now in order to engage the said cover D on the frame part B, I pivot the front bail E thereon in the same relative position and operating in like manner as formerly in connection with the tympan and as is the case with rear bail F; but in this improvement the frame B is adjustable, and since the bail E is pivoted thereon it of course moves with the frame when adjustment occurs. One or more set or thumb screws 7 at the front of the frame B and bearing against the edge of the platen serve to adjust the said frame away from the platen and even out or stretch the cover D, when such stretching of evening out is required. i

In operation the cover D is placed in position in the usual way beneath bails E and F. Sometimes it is found that this is sufficient and that no further efiort is required to make the cover smooth and even. Then, again, it may occur that considerable adj ustment of the frame B is necessary to efiect the required smoothness. By my construction the pressman can do quickly whatever may be required in this behalf, and the platencover can always be brought to the best condition for good work.

What I claim is 1. The platen, a frame-piece for the front of the platen provided with right-angled extremities engaging the sides of the platen and means in said extremities to fix the said piece adj ustably to the platen, and a bail to secure the platen-cover over the edge of said piece, substantially as described.

2. The platen in combination with an adjustable bar at the front edge thereof, having slotted right-angled extremities at the sides of the platen, means to support the bar on the platen through said slots, a pivoted bail supported on said bar and means to adjust the bar relatively to the platen when the platen-cover has been fixed in position, substantially as described.

Witness my hand to the foregoing specification on this 8th day of July, 1897 FRANK A. BURNHAM.

Witnesses:

H. T. Frsnnn, R. B. Mosnn. 

